You can always just put in a Polo exchange wallet address and point your miner at a pool. suprnova.cc would be a good choice - or dwarfpool (I prefer the former for EXP).

I am just selling for BTC immediately at the best price though. Others may wish to hodl and hope for continued price increases. I'd just like the BTC I paid for the GPUs back first. About 50% of the way there,,,,, but then I keep buying more....

I'd say you'll be paying between 250 and 300 for XFX or MSI 290's (generally off ebay). If you went with the 290X, you'd probably be spending closer to 250-350 per depending on your patience and ebay skills.

After that, nicehash stop crediting my hash rate, but local work didn't stop or had errors.Restart mining, get back on nicehash for a small period of time ...Doing my test with a GTX 480 GPU and Win7 64bits. Score around 5MH/sUsing Cuda 0.9.41 and / or ethminer-0.9.41-genoil-1.0.3.Genoil version didn't credit me any hashrate on nicehash.

I ran across an entire pallet of new Sapphire Radeon R7 240 4GB cards. They were at a closeout dealer auction in the Midwest I asked the owner what was going on with them. He said they went through the auction twice already and didn't sell. He said the retailer would let them all go for $40 or $45 ea, I believe there were 170 or 180 of them. I am wondering if this is something that could be useful or are they just too old/small

I grabbed a ASUS R9 290 for 200$ US on Ebay. ( yesterday night )Got lucky on this one, was listed for less than a hour when I jumped on it Efficiency is the prime feature I'm looking for. Don't know about the R7 240, but performance/power consumption ratio is probably not really good.

So these numbers are completely based on intuition and architecture, but I'd expect somewhere in the 10-15 MH range for a 270. I have no idea what the power usage would be. The biggest problem is you also have to get the other components for a rig, which is ~400 bucks on the cheap end of things. Since ETH is kind of unknown in terms of how long mining will happen, it's hard to say if it's worth buying old hardware just to mine ETH.

It's sorta like the problem with buying S4 when S7 is available. Sure, it's a faster payback period, but will it be profitable long enough to pay itself back. That's the gamble.

edit: Ouch, just realized you said R7 240 not 270. Yeah, those are only a couple MH each. The R7 250 is like 3 MH on ETH.